Intelligent Optical Systems (IOS) proposes to develop a new, low cost, compact fiber laser generating femtosecond pulses for multiphoton excitation for a wide range of fluorescence based biomedical applications. The system will consist of a laser diode pumped rare earth doped double clad fiber laser generating powerful (up to 100 muJ) output pulses at 810 nm. This wavelength is currently provided by expensive ($100,000) and bulky (weight with antivibration table approximately 400 kg) Ti:Sapphire lasers. In Phase II, IOS will use this laser for the development of nonlinear fiber devices which will provide ultrashort pulses for multiphoton excitation applications at other wavelengths in the range of 800 to 1600 nm and a powerful ultrawide (400 to 1600 nm) "white" continuum light source for optical coherence tomography. This fiber laser will find application in two- and three- photon induced fluorescence microscopy, two photon correlation spectroscopy, high throughput screening, scanning near field optical fluorescent microscopy, second harmonic generation microscopy and spectroscopy, and optical coherence tomography. PROPOSED COMMERCIAL APPLICATIONS: This femtosecond fiber laser will find application in multiphoton photon induced fluorescence microscopy, two photon correlation spectroscopy, high throughput screening, scanning near field optical fluorescent microscopy, second harmonic generation microscopy and spectroscopy, optical coherence tomography, three dimensional memory, optical data storage, and three-dimensional waveguides formed through two-photon absorption.